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Column originally published May 17, 2000
Column last revised/updated on Oct 1, 2018

Blowing Your Nose Is Not The Main Cause Of Sinus Infection

Question: I get sinus infection very easily. My doctor told me that I have allergies. As you may expect, I blow my nose like a trooper. Lately, I heard that blowing the nose can lead to sinus infection. Is this true? What else can I do when my nose is all clogged up and so uncomfortable?


You have heard it right, in a way. Researchers have recently discovered that blowing the nose can lead to sinus infection. However, there is much more to it. Let me explain this to you in more detail here.

All of us have a number of sinuses inside our head. Sinuses are cavities surrounded by bones, and covered with a very thin layer of tissue called mucosa. The mucosal cells have fine hairs that are constantly moving like a brush. These hairs move the mucus produced by other cells out of the sinus cavity.

The sinuses are located inside our cheekbones (called maxillary sinuses), between the eyes (ethmoidal and sphenoidal sinuses), and above the eyes (frontal sinuses). There are two other small sinuses behind the ears (mastoid sinuses), these drains into the middle ear behind the eardrums.

Some of the sinuses are not well developed in young children. However, because they do have sinuses, even very young children can have sinus infection, although they are much more difficult to recognize.

The most common cause of sinusitis is viral infections like colds and flu. When cold viruses hit, they cause inflammation and swelling in the throat and nasal passage. Common symptoms can include low-grade fever, sneezing, running nose, nasal congestion, and sore throat. The majority of people will get better after several days.

A small percentage of people, however, will go on and develop sinus infection as a complication of the cold. When the mucosa that covers the inside of the nasal passage gets swollen from the virus, it blocks the openings to the sinuses. Mucus that is produced in the sinuses starts to build up. Bacteria can easily invade the sinus cavities and establish sinus infection.

In a similar fashion, allergies like hayfever can lead to sinus infections. The symptoms can be extremely similar to colds. Many people who have allergies think that they get one cold after another. Their real problem is allergy. They can have sneezing, itchy and running nose, and congestion. The mucosa in the nasal passage also gets swollen in nasal allergies, blocking the sinus openings, leading to sinusitis.

In the research that you have heard, volunteers who have colds were asked to cough, sneeze, or blow their nose. A special dye was put inside the nose, and CT scans of the sinuses were obtained afterwards.

What they found was that for those who coughed or sneezed, very little dye was found in the sinuses. However, more dye entered the sinuses after blowing the nose. This implied that bacteria normally present in the nasal passage could be pushed into the sinuses, causing sinus infection.

However, I believe the bigger problem is blockage of sinus openings in colds and allergies. When the sinus openings are unclogged, it is much easier for mucus to drain and harder to establish a sinus infection.

In my own practice, I have seen many patients with mild or early sinus infections. Instead of using antibiotics right away, I have often asked patients to use local decongestants in the nasal passage for several days. They come in nose drops or nose sprays. By using these decongestants, the swelling of mucosa is decreased, opening the sinuses and draining the pus and mucus. Very often, sinus infections and antibiotics can be avoided totally.

You may wonder now, what should you do when you have mucus inside your nose? There are several ways to get rid of it. The mucus can come out from the front or the back. You can let nature does the job, wipe your nose when it drains out, or swallow when it drains back. There is absolutely no harm in swallowing the mucus.

However, most adults tend to blow their nose. Studies have shown that adults blow their nose more than 40 times a day when they have colds. Many children, however, will snort instead. Snorting the mucus will not increase the pressure in the nasal passage, and push bacteria into the sinuses. However, our culture frowns upon people who snort loudly. May be one can do it quietly in the washroom.

Blowing the nose seems to be more acceptable in our society. That is why we have handkerchiefs and tissues. In view of the findings of this research, I think we should be careful in this manoeuvre. The stronger the blow, the greater is the force, and the more likelihood bacteria can be pushed into the sinuses.

My own personal suggestion is not to stop blowing completely, but work harder on keeping the nasal passage and sinus openings clear with the use of local decongestants when you have a cold. You can check with your pharmacists. Some of these decongestants can work for 8 to 12 hours, they can be used two to three times a day when you have a cold. I often suggest my patients to use nasal decongestants for 3 to 5 days without stopping. It is not good to start and stop nasal decongestants; this can lead to “rebound phenomenon” where congestion will reoccur whenever one stops the decongestant.

If allergy is your problem, you should work with your doctor to find ways to reduce the allergy. There may be allergy triggers (like dust, mildew, and animals) or cigarette smoke in your indoor environment. By eliminating or reducing these triggers, your allergy problem can be greatly improved.

You may also benefit from taking allergy medicine. They work by controlling allergic reaction in the nasal mucosa, therefore reducing the swelling and clogging of sinus openings. These can come as medicine by mouth or as nose sprays. They are very safe and can reduce your allergy misery and prevent sinus infections.

Finally, if you have long-standing sinus infection, you may need a longer course of antibiotics than the standard 7 or ten days. Sinus infections, once well established, are quite difficult to treat. Use of local decongestants at the same time can speed up the recovery.

[Note to Readers: There are many other columns that deal with nasal allergy and sinus infection. Use of long-acting antihistamines can reduce allergy symptoms, but you have to use a big enough dose to be effective. Nasal steroids are also safe and useful. Sometimes you have to combine these to get the best benefit.]